It is known to use nematic liquid crystal compounds in electrooptic displays. Such displays are utilized in constantly increasing numbers in watches and other instruments. Such devices are well known to those skilled in the art.
One of the problems encountered in the utilization of nematic liquid crystal materials in such displays is the availability of stable low viscosity nematic compounds which are liquid at near room temperatures and have relatively low transition temperatures to make them practical for use in electro-optic display devices. Further, it is desirable that the nematic liquid crystal material require the application of the minimal amount of potential to obtain the desired effect in order to minimize the power requirements in the display device. Only an extremely limited number of nematic liquid crystal compounds thus far known posses these desired characteristics.
One compound possessing the aforementioned combination of properties is described more fully in copending U.S. patent application Ser. No. 17,635 filed Mar. 5, 1979 entitled "5-Alkyl-2-(4-Cyanophenyl)-1,3-Dioxanes" in the name of Howard Sorkin as inventor and of common assignee herewith. The compound of that patent application is represented by the formula: ##STR2## where R is an alkyl of 1 to 8 carbon atoms. As a result of their somewhat limited nematic range, these compounds are preferably mixed with other liquid crystal materials in order to formulate liquid crystal mixtures with a wide nematic temperature range.